Complex Sinusoids

February 2, 2019 by 3200 Creative

Complex Sinusoids

Question 1 of 4

1. Question
Find the amplitude of the complex sinusoid $x(t) =3e^{j(10\pi t + \pi/2)}$ .
Correct

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Question 2 of 4

2. Question
Find the frequency in rads/sec of the complex sinusoid $x(t) =3e^{j(10\pi t + \pi/2)}$ .
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Question 3 of 4

3. Question
A complex sinusoid is given by $x(t) =3e^{j(10\pi t + \pi/2)}$ . Select all the correct statements.
- Re $\{x(t)\} = \sin(10\pi t +\pi/2)$
- Im $\{x(t)\} = \sin(10\pi t +\pi/2)$
- Re $\{x(t)\} = \cos(10\pi t +\pi/2)$
- Im $\{x(t)\} = \cos(10\pi t +\pi/2)$
Correct

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Question 4 of 4

4. Question
Suppose a signal is a sum of complex sinusoids $x[n] = -2e^{j(\pi/4)n} + 2e^{j(-\pi/4)n}$ . Which of the following expressions are equivalent to $x[n]$ ?
- $-2\cos((\pi/4) n)$
- $-2j\sin((\pi/4) n)$
- $-2\sin((\pi/4) n)$
- $-4j\sin((\pi/4) n)$
- $-4\cos((\pi/4) n)$
Correct

Incorrect